EP2291451B1 - Impact-resistant modified polycarbonate compositions - Google Patents

Description

The present invention relates to age-resistant, impact-modified polycarbonate compositions and molding compounds characterized by an improved balance of multiaxial low-temperature toughness and flowability, good colorability and high heat resistance.

Compositions comprising polycarbonate, graft polymer based on rubber-elastic, aging-stable graft base and vinylaromatic copolymer are known in principle.

DE-A 4434965 For example, those compositions having improved balance of low-temperature toughness, stiffness, and rheology including polycarbonate (A), graft polymer having special particle size rubbery graft bases (B), and vinyl aromatic (co) polymer (C) are disclosed, with the proportions B to C being limited. Silicone acrylate composite rubbers are not disclosed as a rubber elastic graft base in this application.

EP-A 0537014 discloses compositions having improved low temperature toughness containing a thermoplastic resin, eg, a polycarbonate, a vinyl polymer, or a mixture thereof, and an impact modifier amount of a specific multiphase polyorganosiloxane / polyvinyl based graft polymer. Compositions of polycarbonate, vinyl polymer and graft polymer in which the vinyl and the graft polymer are used in a certain amount ratio are not disclosed.

EP-A 0486853 discloses compositions having improved colorability by use of pigments comprising a specific graft polymer based on a polyorganosiloxane-polyalkly (meth) acrylate compound rubber and optionally other thermoplastics such as polycarbonate.

EP-A 0430134 discloses compositions having excellent impact strength, surface hardness and surface quality containing polycarbonate and a specific graft-based polyorganosiloxane graft polymer containing 1-10% by weight of polyorganosiloxane rubber and 99-90% by weight of polyalkyl (meth) acrylate rubber in non-separable form contains. It is further disclosed that the compositions may also contain vinyl monomer based homo- or copolymers. About special Property advantages that arise when using the three components in the special mixing ratio, silent this application.

EP-A 0307963 discloses compositions having good chemical, weathering and heat resistance as well as impact resistance containing polycarbonate, graft polymer based on a silicone-butyl acrylate composite rubber base and vinyl copolymer. However, the disclosed compositions have an unfavorable ratio of graft polymer to vinyl copolymer content. The coloring of such compositions in dark and brilliant colors requires high levels of pigments which lead to a deterioration of the mechanical properties of the composition.

EP-A 1334153 discloses compositions having improved heat aging stability, high surface quality, and good processability including polycarbonate, silicone acrylate composite rubber-based graft polymer, vinyl copolymer, and mineral filler (glass fibers). These compositions have insufficient toughness for many applications, especially at low temperatures.

The object of the present invention is to provide age-stable polycarbonate compositions and molding compositions which are distinguished by an improved balance of multiaxial low-temperature toughness and melt flowability, good dyeability and high heat resistance.

In particular, it is the object of the present invention to provide age-stable polycarbonate compositions which can also be dyed in dark and brilliant colors for unpainted automotive interior components and automobile body parts which show no splintering failure in application-relevant ductility tests down to -10 ° C., a melt viscosity measured at 260 ° C. and a shear rate of 1000 s ^-1 of a maximum of 250 Pas and a heat resistance measured as Vicat B 120 of at least 125 ° C.

1. A) 70 - 80 Gew.-Teile (bezogen auf die Summe der Komponenten A + B + C) aromatisches Polycarbonat und/oder aromatisches Polyestercarbonat,
2. B) 4 - 12 Gew.-Teile, bevorzugt 5 - 10 Gew.-Teile, besonders bevorzugt 6 - 10 Gew.-Teile (bezogen auf die Summe der Komponenten A + B+ C) Pfropfpolymerisat mit
   • B.1 10 bis 50 Gew.-%, vorzugsweise 20 bis 40 Gew.-% (jeweils bezogen auf das Pfropfpolymerisat B) einer Hülle aus mindestens einem Vinylmonomeren und
   • B.2 90 bis 50 Gew.-%, vorzugsweise 80 bis 60 Gew.-%, (jeweils bezogen auf das Pfropfpolymerisat B) einer oder mehrerer Pfropfgrundlagen aus Silikon-Acrylat-Kompositkautschuk,
3. C) 12 - 25 Gew.-Teile, besonders bevorzugt 14 - 20 Gew.-Teile (bezogen auf die Summe der Komponenten A + B+ C) eines Vinylmonomer-basierenden Polymerisats oder Copolymersiats, und
4. D) 0 - 20 Gew.-Teile, bevorzugt 0,1 - 10 Gew.-Teile, besonders bevorzugt 0,2 - 5 Gew.-Teile (bezogen auf die Summe der Komponenten A + B+ C) Polymeradditive,

wobei die Komponenten B und C in einem Verhältnis der Gew.-Teile von B : C im Bereich 1 : 1,3 bis 1 : 3,5, bevorzugt im Bereich 1 : 1,5 bis 1 : 3,0, besonders bevorzugt im Bereich 1 : 1,6 bis 1 : 2,7 vorliegen,
wobei die Zusammensetzung frei von anorganischen Füllstoffen ist, und wobei das Polycarbonat aus Diphenolen hergestellt ist, ausgewählt aus der gruppe, die in Anspruch 1 definiert ist, und
wobei alle Gewichtsteilangaben in der vorliegenden Anmeldung so normiert sind, dass die Summe der Gewichtsteile der Komponenten A+B+C in der Zusammensetzung 100 ergeben,
das gewünschte Eigenschaftsprofil aufweisen.It has surprisingly been found that compositions consisting of

1. A) 70-80 parts by weight (based on the sum of the components A + B + C) of aromatic polycarbonate and / or aromatic polyester carbonate,
2. B) 4 to 12 parts by weight, preferably 5 to 10 parts by weight, more preferably 6 to 10 parts by weight (based on the sum of the components A + B + C) of the graft polymer
   • B.1 10 to 50 wt .-%, preferably 20 to 40 wt .-% (each based on the graft polymer B) of a shell of at least one vinyl monomer and
   • B.2 90 to 50 wt .-%, preferably 80 to 60 wt .-%, (in each case based on the graft polymer B) of one or more graft bases of silicone-acrylate composite rubber,
3. C) 12-25 parts by weight, more preferably 14-20 parts by weight (based on the sum of the components A + B + C) of a vinyl monomer-based polymer or Copolymeriates, and
4. D) 0-20 parts by weight, preferably 0.1-10 parts by weight, more preferably 0.2-5 parts by weight (based on the sum of components A + B + C) of polymer additives,

wherein the components B and C in a ratio of parts by weight of B: C in the range 1: 1.3 to 1: 3.5, preferably in the range 1: 1.5 to 1: 3.0, particularly preferably in Range 1: 1.6 to 1: 2.7,
wherein the composition is free of inorganic fillers, and wherein the polycarbonate is prepared from diphenols selected from the group defined in claim 1, and
wherein all parts by weight in the present application are normalized to give the sum of parts by weight of components A + B + C in the composition 100,
have the desired property profile.

Component A

Aromatic polycarbonates and / or aromatic polyester carbonates according to component A which are suitable according to the invention are known from the literature or can be prepared by processes known from the literature (for the preparation of aromatic polycarbonates, see, for example, Schnell, Chemistry and Physics of Polycarbonates, Interscience Publishers, 1964 and US Pat DE-AS 1 495 626 . DE-A 2 232 877 . DE-A 2 703 376 . DE-A 2 714 544 . DE-A 3 000 610 . DE-A 3 832 396 ; for the preparation of aromatic polyester carbonates, for. B. DE-A 3 077 934 ).

The preparation of aromatic polycarbonates z. Example, by reacting diphenols with carbonic acid halides, preferably phosgene and / or with aromatic dicarboxylic acid dihalides, preferably Benzoldicarbonsäuredihalogeniden by the interfacial process, optionally using chain terminators, for example monophenols and optionally using trifunctional or more than trifunctional branching agents, for example triphenols or tetraphenols. Likewise, preparation via a melt polymerization process by reaction of diphenols with, for example, diphenyl carbonate is possible.

wobei

A

eine Einfachbindung, C₁ bis C₅-Alkylen, C₂ bis C₅-Alkyliden, C₅ bis C₆-Cycloalkyliden,-O-, -SO-, -CO-, -S-, -SO₂-, C₆ bis C₁₂-Arylen, an das weitere aromatische gegebenenfalls Heteroatome enthaltende Ringe kondensiert sein können, oder ein Rest der Formel (II) oder (III)

B

jeweils C₁ bis C₁₂-Alkyl, vorzugsweise Methyl, Halogen, vorzugsweise Chlor und/oder Brom

x

jeweils unabhängig voneinander 0, 1 oder 2,

p

1 oder 0 sind, und

R⁵ und R⁶

für jedes X¹ individuell wählbar, unabhängig voneinander Wasserstoff oder C₁ bis C₆-Alkyl, vorzugsweise Wasserstoff, Methyl oder Ethyl,

X¹

Kohlenstoff und

m

eine ganze Zahl von 4 bis 7, bevorzugt 4 oder 5 bedeuten, mit der Maßgabe, dass an mindestens einem Atom X¹, R⁵ und R⁶ gleichzeitig Alkyl sind.

Diphenols for the preparation of the aromatic polycarbonates and / or aromatic polyester carbonates are preferably those of the formula (I)

in which

A

a single bond, C ₁ to C ₅ alkylene, C ₂ to C ₅ alkylidene, C ₅ to C ₆ cycloalkylidene, -O-, -SO-, -CO-, -S-, -SO ₂ -, C ₆ to C ₁₂ -aryl, to which further aromatic rings containing optionally heteroatoms may be condensed, or a radical of the formula (II) or (III)

B

in each case C ₁ to C ₁₂ -alkyl, preferably methyl, halogen, preferably chlorine and / or bromine

x

each independently 0, 1 or 2,

p

1 or 0 are, and

R ⁵ and R ⁶

individually selectable for each X ¹ , independently of one another hydrogen or C ₁ to C ₆ -alkyl, preferably hydrogen, methyl or ethyl,

X ¹

Carbon and

m

an integer from 4 to 7, preferably 4 or 5, with the proviso that on at least one atom X ¹ , R ⁵ and R ^{6 are} simultaneously alkyl.

Preferred diphenols are hydroquinone, resorcinol, dihydroxydiphenols, bis (hydroxyphenyl) -C ₁ -C ₅ alkanes, bis (hydroxyphenyl) -C ₅ -C ₆ -cycloalkanes, bis (hydroxyphenyl) ethers, bis (hydroxyphenyl) - sulfoxides, bis (hydroxyphenyl) ketones, bis (hydroxyphenyl) sulfones and α, α-bis (hydroxyphenyl) -diisopropyl-benzenes and their nuclear-brominated and / or nuclear-chlorinated derivatives. Particularly preferred diphenols are 4,4'-dihydroxydiphenyl, bisphenol-A, 2,4-bis (4-hydroxyphenyl) -2-methylbutane, 1,1-bis (4-hydroxyphenyl) -cyclohexane, 1,1- Bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 4,4'-dihydroxydiphenylsulfide, 4,4'-dihydroxydiphenylsulfone and their di- and tetrabrominated or chlorinated derivatives such as, for example, 2,2-bis (3-chloro-4-bis) hydroxyphenyl) -propane, 2,2-bis (3,5-dichloro-4-hydroxyphenyl) -propane or 2,2-bis (3,5-dibromo-4-hydroxyphenyl) -propane. Particularly preferred is 2,2-bis (4-hydroxyphenyl) propane (bisphenol-A). The diphenols can be used individually or as any mixtures. The diphenols are known from the literature or obtainable by literature methods.

Chain terminators suitable for the preparation of the thermoplastic, aromatic polycarbonates are, for example, phenol, p-chlorophenol, p-tert-butylphenol or 2,4,6-tribromophenol, but also long-chain alkylphenols, such as 4- [2- (2,4,4 -Trimethylpentyl)] - phenol, 4- (1,3-tetramethylbutyl) phenol according to DE-A 2 842 005 or monoalkylphenol or dialkylphenols having a total of 8 to 20 carbon atoms in the alkyl substituents such as 3,5-di-tert-butylphenol, p-iso-octylphenol, p-tert-octylphenol, p-dodecylphenol and 2- (3,5- Dimethylheptyl) phenol and 4- (3,5-dimethylheptyl) phenol. The amount of chain terminators to be used is generally between 0.5 mol%, and 10 mol%, based on the molar sum of the diphenols used in each case.

The thermoplastic, aromatic polycarbonates may be branched in a known manner, preferably by the incorporation of from 0.05 to 2.0 mol%, based on the sum of the diphenols used, of trifunctional or more than trifunctional compounds, for example those containing three and more phenolic groups.

Both homopolycarbonates and copolycarbonates are suitable. For the preparation of inventive copolycarbonates according to component A, it is also possible to use from 1 to 25% by weight, preferably from 2.5 to 25% by weight, based on the total amount of diphenols to be used, of hydroxyaryloxy endblocked polydiorganosiloxanes. These are known ( US 3 419 634 ) and produced by literature methods. The preparation of polydiorganosiloxane-containing copolycarbonates is described in U.S. Patent Nos. 4,378,399 and 5,605,842 DE-A 3 334 782 described.

Preferred polycarbonates are, in addition to the bisphenol A homopolycarbonates, the copolycarbonates of bisphenol A with up to 15 mol%, based on the molar amounts of diphenols, of other than preferred or particularly preferred diphenols, in particular 2,2-bis (3,5 dibromo-4-hydroxyphenyl) propane.

Aromatic dicarboxylic acid dihalides for the preparation of aromatic polyester carbonates are preferably the diacid dichlorides of isophthalic acid, terephthalic acid, diphenyl ether-4,4'-dicarboxylic acid and naphthalene-2,6-dicarboxylic acid.

Particularly preferred are mixtures of the diacid dichlorides of isophthalic acid and terephthalic acid in the ratio between 1:20 and 20: 1.
In the production of polyester carbonates, a carbonyl halide, preferably phosgene, is additionally used as the bifunctional acid derivative.

As chain terminators for the preparation of the aromatic polyester are in addition to the aforementioned monophenols still their chloroformate and the acid chlorides of aromatic monocarboxylic acids, which may be substituted by C ₁ to C ₂₂ alkyl groups or by halogen atoms, and aliphatic C ₂ to C ₂₂ monocarboxylic acid chlorides into consideration.

The amount of chain terminators is in each case 0.1 to 10 mol%, based on moles of diphenol in the case of the phenolic chain terminators and on moles of dicarboxylic acid dichloride in the case of monocarboxylic acid chloride chain terminators.
The aromatic polyester carbonates may also contain incorporated aromatic hydroxycarboxylic acids.

The aromatic polyester carbonates can be branched both linearly and in a known manner (see DE-A 2 940 024 and DE-A 3 007 934 ).

Examples of suitable branching agents are trifunctional or polyfunctional carboxylic acid chlorides, such as trimesic acid trichloride, cyanuric trichloride, 3,3 ', 4,4'-benzophenone-tetracarboxylic acid tetrachloride, 1,4,5,8-naphthalene tetracarboxylic acid tetrachloride or pyromellitic acid tetrachloride, in amounts of 0.01 to 1.0 mol% (based on dicarboxylic acid dichlorides used) or trifunctional or polyfunctional phenols, such as phloroglucinol, 4,6-dimethyl-2,4,6-tri- (4-hydroxyphenyl) -hept-2-ene, 4 , 6-Dimethyl-2,4,6-tris (4-hydroxyphenyl) heptane, 1,3,5-tris (4-hydroxyphenyl) benzene, 1,1,1-tri- (4-hydroxyphenyl) ethane, tri (4-hydroxyphenyl) phenylmethane, 2,2-bis [4,4-bis (4-hydroxy-phenyl) -cyclohexyl] -propane, 2,4-bis (4-hydroxyphenyl-isopropyl ) -phenol, tetra (4-hydroxyphenyl) -methane, 2,6-bis (2-hydroxy-5-methylbenzyl) -4-methyl-phenol, 2- (4-hydroxyphenyl) -2- (2, 4-dihydroxyphenyl) -propane, tetra- (4- [4-hydroxyphenyl-isopropyl] -phenoxy) -methane, 1,4-bis [4,4'-dihydroxytri-phenyl) -methyl] -benzene, in amounts from 0.01 bi s 1.0 mol% based on used Diphenols are used. Phenolic branching agents can be introduced with the diphenols, acid chloride branching agents can be added together with the acid dichlorides.

In the thermoplastic, aromatic polyester carbonates, the proportion of carbonate structural units can vary as desired. The proportion of carbonate groups is preferably up to 100 mol%, in particular up to 80 mol%, particularly preferably up to 50 mol%, based on the sum of ester groups and carbonate groups. Both the ester and the carbonate portion of the aromatic polyester carbonates may be present in the form of blocks or randomly distributed in the polycondensate.

In a preferred embodiment of the invention, the aromatic polycarbonates and the aromatic polyester carbonates have a weight-average molecular weight (M _w , measured, for example, by GPC, ultracentrifuge or scattered light measurement) of 22,000 to 32,000 g / mol, more preferably 24,000 to 28,000 g / mol.

The thermoplastic, aromatic polycarbonates and polyester carbonates can be used alone or in any desired mixture.

Component B

The graft copolymers B are generally prepared by free-radical polymerization, e.g. by emulsion, suspension, solution or bulk polymerization, preferably by emulsion polymerization.

Suitable monomers B.1 are vinyl monomers such as vinylaromatics and / or ring-substituted vinylaromatics (such as styrene, α-methylstyrene, p-methylstyrene, p-chlorostyrene), methacrylic acid (C ₁ -C ₈ ) -alkyl esters (such as methyl methacrylate, ethyl methacrylate, 2- Ethylhexyl methacrylate, allyl methacrylate), acrylic acid (C ₁ -C ₈ ) alkyl esters (such as methyl acrylate, ethyl acrylate, n-butyl acrylate, t-butyl acrylate), organic acids (such as acrylic acid, methacrylic acid), and / or vinyl cyanides (such as acrylonitrile and methacrylonitrile) , and / or derivatives (such as anhydrides and imides) of unsaturated carboxylic acids (for example, maleic anhydride and N-phenyl-maleimide). These vinyl monomers can be used alone or in mixtures of at least two monomers.

Preferred monomers B.1 are selected from at least one of the monomers styrene, methyl methacrylate, n-butyl acrylate and acrylonitrile. Particular preference is given to using methyl methacrylate or a mixture of styrene and acrylonitrile as monomer B.1.

The glass transition temperature of the graft B.2 is <10 ° C, preferably <0 ° C, more preferably <-20 ° C. The graft base B.2 has, in general, an average particle size (d ₅₀ value) of 0.05 to 10 microns, preferably 0.06 to 5 .mu.m, particularly preferably 0.1 to 1 microns.

The mean particle size (d ₅₀ value) is the diameter, above and below which each 50 wt .-% of the particles are. He can by means of Ultrazentrifugenmessung ( W. Scholtan, H. Lange, Colloid-Z. and Z. Polymere 250 (1972), 782-796 ).

The graft base B.2) are composite rubbers of silicone rubber and acrylate rubber, wherein, for example, these two types of rubber are present as a physical mixture or wherein, for example, the silicone rubber and acrylate rubber form an interpenetrating network or, for example, the silicone rubber and acrylate rubber form a graft base which forms a core shell. Structure has. Preferred grafting bases B.2) are composite rubbers of 10 to 70% by weight, particularly preferably 20 to 60% by weight of silicone rubber and 90 to 30% by weight, particularly preferably 80 to 40% by weight of butyl acrylate rubber (the statement of Wt .-% is here in each case based on the graft B.2).

The silicone acrylate rubbers are preferably composite rubbers with grafting sites, wherein the silicone rubber and acrylate rubber in the composite rubber interpenetrate each other so that they do not differ significantly from each other.

Silicone acrylate rubbers are known and described, for example, in US 5,807,914 . EP 430134 and US 4888388 ,

Silicone rubber components of the silicone acrylate rubber according to B.2 are preferably prepared by emulsion polymerization, in which the siloxane monomer building blocks, crosslinking or branching agent (IV) and optionally grafting agent (V) are used.

Examples of preferred siloxane monomer building blocks are dimethylsiloxane or cyclic organosiloxanes having at least 3 ring members, preferably 3 to 6 ring members, such as for example, and preferably hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, trimethyl-triphenyl-cyclotrisiloxane, tetramethyl-tetraphenyl-cyclotetrasiloxane, Octaphenylcyclotetrasiloxan used.

The organosiloxane monomers can be used alone or in the form of mixtures with 2 or more monomers. The silicone rubber preferably contains not less than 50% by weight and more preferably not less than 60% by weight of organosiloxane, based on the total weight of the silicone rubber component.

As crosslinking or branching agent (IV) it is preferred to use silane-based crosslinking agents having a functionality of 3 or 4, more preferably 4. Examples which may be mentioned are: trimethoxymethylsilane, triethoxyphenylsilane, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane and tetrabutoxysilane. The crosslinking agent may be used alone or in a mixture of two or more. Particularly preferred is tetraethoxysilane.

The crosslinking agent is used in an amount ranging between 0.1 and 40% by weight based on the total weight of the silicone rubber component. The amount of crosslinking agent is chosen such that the degree of swelling of the silicone rubber, measured in toluene, is between 3 and 30, preferably between 3 and 25, and more preferably between 3 and 15. The degree of swelling is defined as the weight ratio between the amount of toluene, which is absorbed by the silicone rubber when saturated with toluene at 25 ° C and the amount of silicone rubber in the dried state. The determination of the degree of swelling is described in detail in EP 249964 described.

Tetrafunctional crosslinking agents are preferred over trifunctional because then the degree of swelling is easier to control within the limits described above.

R¹

für C₁-C₄-Alkyl, vorzugsweise Methyl, Ethyl oder Propyl, oder Phenyl,

R²

für Wasserstoff oder Methyl stehen,

n

0, 1 oder 2 und

p

eine ganze Zahl von 1 bis 6 bedeuten.

Suitable as the grafting agent (V) are compounds capable of forming structures of the following formulas:

CH ₂ = C (R ² ) -COO- (CH ₂ ) _p -SiR ¹ _n O _{(3-n) / 2} (V-1)

CH ₂ = CH-SiR ¹ _n O _{(3-n) / 2} (V-2)

or

HS- (CH ₂ ) _p -SiR ¹ _n O _{(3-n) / 2} (V-3),

in which

R ¹

C ₁ -C ₄ -alkyl, preferably methyl, ethyl or propyl, or phenyl,

R ²

represent hydrogen or methyl,

n

0, 1 or 2 and

p

an integer from 1 to 6.

Acryloyl or methacryloyloxysilanes are particularly suitable, the o.g. Structure (V-1) to form, and have a high grafting efficiency. This ensures effective formation of the graft chains and thus favors the impact resistance of the resulting resin composition. Examples and preferred are: β-methacryloyloxy-ethyldimethoxymethyl-silane, γ-methacryloyloxy-propylmethoxydimethyl-silane, γ-methacryloyloxy-propyldimethoxymethyl-silane, γ-methacryloyloxy-propyltrimethoxy-silane, γ-methacryloyloxy-propylethoxydiethyl-silane, γ-methacryloyloxy propyldiethoxymethyl-silane, δ-methacryloyl-oxy-butyldiethoxymethyl-silanes or mixtures thereof.

Preference is given to using from 0 to 20% by weight of grafting agent, based on the total weight of the silicone rubber.

The silicone rubber can be prepared by emulsion polymerization, such as in US 2891920 and US 3294725 described. The silicone rubber is obtained in the form of an aqueous latex. For this purpose, a mixture comprising organosiloxane, crosslinking agent and optionally grafting agent is mixed under shear with water, for example by a homogenizer, in the presence of an emulsifier in a preferred embodiment sulfonic acid such as alkylbenzenesulfonic acid or alkylsulfonic acid, wherein the mixture polymerized to the silicone rubber latex. Particularly suitable is an alkylbenzenesulfonic acid, since it acts not only as an emulsifier but also as a polymerization initiator. In this case, a combination of the sulfonic acid with a metal salt of an alkylbenzenesulfonic acid or with a metal salt of an alkylsulfonic acid is favorable because it stabilizes the polymer during the later graft polymerization.

After the polymerization, the reaction is terminated by neutralizing the reaction mixture by adding an aqueous alkaline solution, e.g. by adding an aqueous sodium hydroxide, potassium hydroxide or sodium carbonate solution.

Suitable polyalkyl (meth) acrylate rubber components of the silicone acrylate rubbers according to B.2 can be prepared from alkyl methacrylates and / or alkyl acrylates, a crosslinking agent (VI) and a grafting agent (VII). Here are exemplary and preferred alkyl methacrylates and / or alkyl acrylates are the C ₁ to C ₈ alkyl esters, for example methyl, ethyl, n-butyl, t-butyl, n-propyl, n-hexyl, n-octyl, n-lauryl and 2-ethylhexyl ester; Haloalkyl, preferably halo-C ₁ -C ₈ alkyl esters, such as chloroethyl acrylate and mixtures of these monomers. Particularly preferred is n-butyl acrylate.

As the crosslinking agent (VI) for the polyalkyl (meth) acrylate rubber component of the silicone acrylate rubber, monomers having more than one polymerizable double bond can be used. Preferred examples of crosslinking monomers are esters of unsaturated monocarboxylic acids having 3 to 8 C atoms and unsaturated monohydric alcohols having 3 to 12 C atoms, or saturated polyols having 2 to 4 OH groups and 2 to 20 C atoms, such as ethylene glycol dimethacrylate, propylene glycol dimethacrylate , 1,3-butylene glycol dimethacrylate and 1,4-butylene glycol dimethacrylate. The crosslinkers may be used alone or in mixtures of at least two crosslinkers.

Exemplary and preferred grafting agents (VII) are allyl methacrylate, triallyl cyanurate, triallyl isocyanurate or mixtures thereof. Allyl methacrylate can also be used as crosslinking agent (VI). The grafting agents may be used alone or in mixtures of at least two grafting agents.

The amount of crosslinking agent (VI) and grafting agent (VII) is 0.1 to 20% by weight based on the total weight of the polyalkyl (meth) acrylate rubber component of the silicone acrylate rubber.

The silicone acrylate rubber is prepared by first preparing the silicone rubber according to B.2.1 as an aqueous latex. This latex is then enriched with the alkyl methacrylates and / or alkyl acrylates to be used, the crosslinking agent (VI) and the grafting agent (VII), and polymerization is carried out. Preference is given to a free-radically initiated emulsion polymerization, for example by means of a peroxide, an azo or redox initiator. Particularly preferred is the use of a redox initiator system, especially a sulfoxylate initiator system prepared by combining iron sulfate, disodium ethylenediaminetetraacetate, Rongalit and hydroperoxide.

The grafting agent (V) used in the preparation of the silicone rubber causes the polyalkyl (meth) acrylate rubber portion to be covalently bonded to the silicone rubber portion. In the polymerization, the two rubber components penetrate each other and thus form the composite rubber, which does not become more after the polymerization can be separated into its components of silicone rubber component and polyalkyl (meth) acrylate rubber component.

For the preparation of the silicone acrylate graft polymers B mentioned as component B), the monomers B.1 are added to the rubber base B.2. grafted.

In this case, for example, in EP 249964 . EP 430134 and US 4888388 described polymerization methods are used.

For example, the graft polymerization is carried out according to the following polymerization method: In a one-stage or multistage free-radically initiated emulsion polymerization, the desired vinyl monomers B.1 are grafted onto the graft base, which is in the form of an aqueous latex. The grafting efficiency should be as high as possible and is preferably greater than or equal to 10%. The grafting efficiency depends largely on the grafting agent (V) or (VII) used. After polymerization to the silicone (acrylate) graft rubber, the aqueous latex is placed in hot water, in which metal salts have previously been dissolved, e.g. Calcium chloride or magnesium sulfate. The silicone coats (acrylate) graft rubber and can then be separated.

Component C

• C.1 50 bis 99 Gew.-Teilen, vorzugsweise 60 bis 80 Gew.-Teilen, insbesondere 72 bis 78 Gew.-Teilen (bezogen auf Komponente C) Vinylaromaten und/oder kernsubstituierten Vinylaromaten wie Styrol, α-Methylstyrol, p-Methylstyrol, p-Chlorstyrol) und/oder (Meth)Acrylsäure-(C₁-C₈)-Alkylester, wie Methylmethacrylat, Ethylmethacrylat, und
• C.2 1 bis 50 Gew.-Teilen, vorzugsweise 20 bis 40 Gew.-Teilen, insbesondere 22 bis 28 Gew.-Teilen (bezogen auf Komponente C) Vinylcyanide (ungesättigte Nitrile) wie Acrylnitril und Methacrylnitril und/oder (Meth)Acrylsäure-(C₁-C₈)-Alkylester, wie Methylmethacrylat, n-Butylacrylat, t-Butylacrylat, und/oder ungesättigte Carbonsäuren, wie Maleinsäure, und/oder Derivate, wie Anhydride und Imide, ungesättigter Carbonsäuren, beispielsweise Maleinsäureanhydrid und N-Phenylmaleinimid).

Suitable vinyl (co) polymers C polymers of at least one monomer from the group of vinyl aromatics, vinyl cyanides (unsaturated nitriles), (meth) acrylic acid (C ₁ -C ₈ ) alkyl esters, unsaturated carboxylic acids and derivatives (such as anhydrides and imides ) unsaturated carboxylic acids. Particularly suitable are (co) polymers of

• C.1 50 to 99 parts by weight, preferably 60 to 80 parts by weight, in particular 72 to 78 parts by weight (based on component C) of vinylaromatics and / or ring-substituted vinylaromatics such as styrene, α-methylstyrene, p-methylstyrene , p-chlorostyrene) and / or (meth) acrylic acid (C ₁ -C ₈ ) alkyl esters, such as methyl methacrylate, ethyl methacrylate, and
• C.2 1 to 50 parts by weight, preferably 20 to 40 parts by weight, in particular 22 to 28 parts by weight (based on component C) of vinyl cyanides (unsaturated nitriles) such as acrylonitrile and methacrylonitrile and / or (meth) acrylic acid - (C ₁ -C ₈ ) -alkyl esters, such as methyl methacrylate, n-butyl acrylate, t-butyl acrylate, and / or unsaturated carboxylic acids, such as maleic acid, and / or derivatives such as anhydrides and imides, unsaturated carboxylic acids, for example maleic anhydride and N-phenylmaleimide ).

The vinyl (co) polymers C are resinous, thermoplastic and rubber-free. Polymethyl methacrylate (PMMA) or a vinyl copolymer containing at least 70 parts by weight (based on component C) of methyl methacrylate and up to 30 parts by weight (based on component C) of at least one comonomer selected from the group of styrene, is particularly preferred as component C, n-butyl acrylate, t-butyl acrylate and ethyl acrylate used. A preferred vinyl copolymer C is also a copolymer of C.1 styrene and C.2 acrylonitrile.

The (co) polymers according to C are known and can be prepared by free-radical polymerization, in particular by emulsion, suspension, solution or bulk polymerization. The (co) polymers preferably have average molecular weights Mw (weight average, determined by light scattering or sedimentation) of between 15,000 and 200,000.

Component D

The composition may contain other commercially available polymer additives such as flame retardants, flame retardant synergists, anti-dripping agents (for example compounds of the fluorinated polyolefins, silicones and aramid fibers), lubricants and mold release agents (for example pentaerythritol tetrastearate), nucleating agents, stabilizers, antistatic agents (for example carbon blacks, carbon fibers, carbon nanotubes and organic antistatics such as polyalkylene ethers, alkylsulfonates or polyamide-containing polymers), as well as dyes and pigments in amounts which do not damage the mechanical properties of the composition to such an extent that the target property profile (no splintering failure at -10 ° C) is no longer met.

The flame retardants used are preferably phosphorus-containing flame retardants, in particular those selected from the groups of mono- and oligomeric phosphoric and phosphonic acid esters, phosphonatoamines and phosphazenes, it also being possible to use mixtures of a plurality of components selected from one or more of these groups as flame retardants. Other not specifically mentioned here, preferably halogen-free phosphorus compounds can be used alone or in any combination with other preferably halogen-free phosphorus compounds. For example, are suitable as phosphorus compounds: tributyl phosphate, triphenyl phosphate, tricresyl phosphate, Diphenylkresylphosphat, Diphenyloctylphosphat, diphenyl-2-ethylcresyl phosphate, tri- (isopropylphenyl) phosphate, resorcinol bridged di- or oligophosphate and bisphenol A bridged di- or oligophosphate. The use of oligomeric phosphoric acid esters derived from bisphenol A is particularly preferred. Suitable flame retardants phosphorus compounds are known (see, for example EP-A 0 363 608 . EP-A 0 640 655 ) or let yourself according to known methods in an analogous manner (eg Ullmanns Enzyklopadie der technischen Chemie, Vol. 18, p. 301 ff. 1979 ; Houben-Weyl, Methods of Organic Chemistry, Vol. 12/1, p. 43 ; Beilstein Vol. 6, p. 177 ).

Production of the molding compositions and moldings

The thermoplastic molding compositions of the invention are prepared by mixing the respective components in a known manner and melt-compounded at temperatures of 200 ° C to 340 ° C, preferably at 240 to 300 ° C in conventional units such as internal mixers, extruders and twin-screw and melt-extruded.

The mixing of the individual constituents can be carried out in a known manner both successively and simultaneously, both at about 20 ° C. (room temperature) and at a higher temperature.

The invention also provides processes for the preparation of the molding compositions and the use of the molding compositions for the production of moldings.

The molding compositions of the invention can be used for the production of moldings of any kind. These can be produced for example by injection molding, extrusion and blow molding. Another form of processing is the production of moldings by deep drawing from previously prepared plates or films.

Examples of such moldings are films, profiles, housing parts of any kind, e.g. for household appliances such as juice presses, coffee machines, blenders; for office machines such as monitors, flat screens, notebooks, printers, copiers; Panels, pipes, electrical installation ducts, windows, doors and other profiles for the building sector (interior and exterior applications) and electrical and electronic parts such as switches, plugs and sockets, as well as body and interior components for commercial vehicles, in particular for the automotive sector.

The molding compositions according to the invention can also be used, for example, for the production of the following moldings or moldings: interior fittings for rail vehicles, ships, aircraft, buses and other motor vehicles, housings of electrical appliances containing small transformers, housings for information processing and transmission equipment, housings and cladding of medical equipment , Massagers and housings therefor, toy vehicles for children, flat wall elements, housings for safety devices, heat-insulated Transport containers, fittings for sanitary and bath equipment, grilles for ventilation openings and housings for garden tools.

The molding compositions of the invention are particularly suitable for the production of (unpainted) automotive interior components and body parts, which must withstand the influence of light, heat and possibly weathering.

The following examples serve to further illustrate the invention.

Examples Component A1

Linear polycarbonate based on bisphenol-A with a weight-average molecular weight M _w of 25,000 g / mol (determined by GPC).

Component B1

Graft polymer consisting of 28 wt .-% styrene-acrylonitrile copolymer as a shell with a ratio of styrene to acrylonitrile of 71:29 to 72 wt .-% of a graft as the core consisting of 46 wt .-% silicone rubber and 54 wt .-% butyl acrylate rubber , prepared in emulsion polymerization.

Component B2 (comparison)

Graft polymer consisting of 40 wt .-% styrene-acrylonitrile copolymer with a ratio of styrene to acrylonitrile of 72: 28 wt .-% as a shell to 60 wt .-% of a particulate graft as a core consisting of pure polybutadiene rubber, prepared in emulsion.

Component B3 (comparison)

Graft polymer consisting of 39 wt .-% styrene-acrylonitrile copolymer as a shell to 61 wt .-% of a graft as the core consisting of butyl acrylate rubber, prepared in emulsion.

Component B4 (comparison)

Graft polymer consisting of 40 wt .-% styrene-acrylonitrile copolymer with a ratio of styrene to acrylonitrile of 76: 24 wt .-% as a shell to 60 wt .-% of a silicone rubber graft as a core, prepared in emulsion.

Component C

Styrene / aryl nitrile copolymer having a styrene / acrylonitrile weight ratio of 76:24 wt .-% and an average molecular weight Mw of 100,000 g / mol (measured by GPC in dimethylformamide at 20 ° C).

Component D

• D1: Pentaerythritol tetrastearate as lubricant / release agent
• D2: thermal stabilizer Irganox ^® B 900, Ciba Specialty Chemicals.
• D3: UV protection agent Tinuvin 329, Ciba Specialty Chemicals
• D4: Black Pearls 800, Cabot Europa GIE, Suresnes, France

Production and testing of molding compounds

On a twin-screw extruder (ZSK-25) (Werner and Pfleiderer), the starting materials listed in Table 1 at a speed of 225 rpm and a throughput of 20 kg / h at a melt temperature of 260 ° C and with a degassing vacuum of 100 mbar compounded and subsequently granulated. The finished granules are processed on an injection molding machine to the corresponding test specimens (melt temperature 260 ° C, mold temperature 80 ° C).

The following methods are used to characterize the properties of the specimens:

As a measure of the low-temperature ductility in the practice-relevant impact / crash test, the behavior in the multiaxial penetration test serves. The penetration test carried out in accordance with ISO 6603-2 at a temperature of -10 ° C on test specimens measuring 60 mm x 60 mm x 2 mm. On the one hand, the maximum energy consumption is determined, on the other hand, in particular, the fracture patterns of a total of ten test specimens are assessed as to whether in the majority (at least 90%) of the tests, i. At least 9 out of 10 experiments show splinter-free failure.

As a measure of the heat resistance, the Vicat B120 value measured in accordance with ISO 306 on test specimens of dimensions 80 mm x 10 mm x 4 mm.

As a measure of the melt flowability in injection molding, the melt viscosity at 260 ° C and a shear rate of 1000 s ^-1 measured in accordance with ISO 11443.

The measure of dyeability is the L value measured on compositions containing 0.75 parts by weight of carbon black in reflection in accordance with DIN 6174. Table 1: Compositions and their properties composition 1 2 3 4 5 6 7 8th [Parts by weight] (See.) (See.) (See.) (See.) (See.) (See.) A-1 75 75 75 75 75 75 75 75 B-1 4 7 9 12 B-2 7 B-3 7 3.5 B-4 7 3.5 C-1 21 18 16 13 18 18 18 18 D-1 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 D-2 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 D-3 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 D-4 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 Weight ratio of B: C 1: 5,25 1: 2.57 1: 1.78 1: 1.08 1: 2.57 1: 2.57 1: 2.57 1: 2.57 Double bond-free rubber Yes Yes Yes Yes No Yes Yes Yes properties splintering fracture behavior at -10 ° C Yes No No No No Yes No Yes Energy intake at -10 ° C [J] 39 42 38 39 38 28 41 41 Melt viscosity (260 ° C / 1000s ^-1 ) [Pas] 214 227 230 260 230 210 228 228 Vicat B120 [° C] 132 132 132 132 132 131 132 132 Reflection L 28.6 29.8 29.8 30.3 27.9 27.4 31.6 29.2

The examples in Table 1 show that the property advantages according to the object of this invention result only in those compositions in which graft polymer B and vinyl (co) polymer C are present in the ratio determined according to the invention and, as graft polymer B, one based on a silicone rubber. Acrylate composite rubber is used as a grafting base (see Examples 2 and 3 according to the invention). If the graft polymer B exceeds the permissible proportion, molding compositions with poor colorability and high melt viscosity, i. poor processing performance (Comparative Example 4). If too little graft polymer B is used, the result is insufficient multiaxial low-temperature ductility (Comparative Example 1).

The use of pure acrylate rubber-based graft polymer also results in insufficient multiaxial low-temperature ductility (Comparative Example 6). Use of pure silicone rubber-based graft polymer results in poor dyeability (Comparative Example 7). If a mixture of two graft polymers based on a) pure acrylate rubber and b) pure silicone rubber is used, this in turn results in insufficient multiaxial low-temperature ductility (Comparative Example 8). Although good ductility, flowability and colorability are realized when using butadiene rubber-based graft polymers (Comparative Example 5), such compositions naturally exhibit, due to the oxidation-sensitive, because unsaturated rubber base, insufficient aging resistance to heat, light and weather influences for many applications.

Claims (14)

1. A composition consisting of:

   A) from 70 to 80 parts by weight, based on the sum of components A + B + C, of an aromatic polycarbonate and/or an aromatic polyester carbonate,

   B) from 4 to 12 parts by weight, based on the sum of components A + B + C, of a graft polymer comprising

   B.1 from 10 to 50 wt. %, based on the graft polymer B, of a shell of at least one vinyl monomer, and

   B.2 from 90 to 50 wt. %, based on the graft polymer B, of a graft base of a silicone-acrylate composite rubber,

   C) from 12 to 25 parts by weight, based on the sum of components A + B + C, of a resinous, thermoplastic and rubber-free polymer or copolymer based on a vinyl monomer, and

   D) from 0 to 20 parts by weight of polymer additives,

   wherein components B and C are present in a ratio of the parts by weight of B:C in a range from 1:1.3 to 1:3.5, and wherein the composition is free of inorganic fillers, and wherein the polycarbonate is prepared from diphenols selected from the group consisting of dihydroxydiphenols, bis(hydroxyphenyl)-C₁-C₅-alkanes, bis(hydroxyphenyl)-C₅-C₆-cycloalkanes, bis(hydroxylphenyl)ethers, bis(hydroxyphenyl) sulfoxides, bis(hydroxyphenyl) ketones, bis(hydroxyphenyl) sulfones, and a,a,-bis(hydroxyl-phenyl)diisopropylbenzenes and also their ring-brominated and/or ring-chlorinated derivatives and 1,1-bis(4-hydroxyphenyl)-3.3.5-trimethylcyclohexane, and wherein all parts by weight in the present application are standardized such that the sum of the parts by weight of components A+B+C in the composition is 100.
2. A composition according to claim 1, comprising

   A) from 70 to 80 parts by weight, based on the sum of components A + B + C, of an aromatic polycarbonate and/or an aromatic polyester carbonate,

   B) from 6 to 10 parts by weight, based on the sum of components A + B + C, of a graft polymer,

   C) from 14 to 20 parts by weight, based on the sum of components A + B + C, of a polymer or copolymer based on a vinyl monomer, and

   D) from 0.2 to 5 parts by weight, based on the sum of components A + B + C, of polymer additives,

   wherein components B and C are present in a ratio of the parts by weight of B:C in a range from 1:1.6 to 1:2.7.
3. A composition according to claim 1 or 2 comprising as the graft base B.2, a composite rubber comprising from 10 to 70 wt. % silicone rubber and from 90 to 30 wt. % butyl acrylate rubber, based in each case on the weight of graft base B.2.
4. A composition according to claim 3 comprising as the graft base B.2, a composite rubber comprising from 20 to 60 wt. % silicone rubber and from 80 to 40 wt. % butyl acrylate rubber, based in each case on the weight of graft base B.2.
5. A composition according to claim 1 to 4 comprising as component A, an aromatic polycarbonate and/or aromatic polyester carbonate having a weight-average molecular weight M_w, measured, for example, by GPC, ultracentrifuge or scattered-light measurement, of from 22,000 to 32,000 g/mol.
6. A composition according to claim 5 comprising as component A, an aromatic polycarbonate and/or aromatic polyester carbonate having a weight-average molecular weight of from 24,000 to 28,000 g/mol.
7. A composition according to claim 1 to 6 comprising as the graft base B.2, a silicone-acrylate composite rubber having graft-active sites, wherein the silicone rubber and the acrylate rubber interpenetrate in the composite rubber so that said silicone rubber and said acrylate rubber cannot substantially be separated from each another.
8. A composition according to claim 1 to 7 comprising as the graft shell B.1, a methyl methacrylate or a mixture of styrene and acrylonitrile.
9. A composition according to claim 1 to 8 comprising as component C, (co)polymers of

   C.1 from 50 to 99 parts by weight of a vinyl aromatic compound and/or a vinyl aromatic compound substituted on the ring and/or a (meth)acrylic acid (C₁-C₈)-alkyl ester, and

   C.2 from 1 to 50 parts by weight of a vinyl cyanide and/or a (meth)acrylic acid (C₁-C₈)-alkyl ester and/or an unsaturated carboxylic acid and/or an anhydride of an unsaturated carboxylic acid and an imide of an unsaturated carboxylic acid.
10. A composition according to claim 9 comprising as component C, a copolymer of C.1 styrene and C.2 acrylonitrile.
11. A composition according to claim 9 comprising as component C, polymethyl methacrylate (PMMA) or a vinyl copolymer comprising at least 70 parts by weight, based on component C, of methyl methacrylate and up to 30 parts by weight, based on component C, of at least one comonomer selected from the group consisting of styrene, n-butyl acrylate, tert-butyl acrylate and ethyl acrylate.
12. A composition according to claim 1 to 11 comprising as component D, at least one polymer additive selected from the group consisting of flameproofing agents, flameproofing synergists, antidripping agents, lubricants and mould release agents, nucleating agents, stabilisers, antistatics, colourings and pigments.
13. The use of the composition according to claim 1 to 12 for producing mouldings.
14. A moulding comprising a composition according to claim 1 to 12.